/*
 * Copyright (c) 2019, Oracle and/or its affiliates. All rights reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *  http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 */

package org.eclipse.imagen.media.opimage;

import java.awt.Rectangle;
import java.awt.image.DataBuffer;
import java.awt.image.Raster;
import java.awt.image.RenderedImage;
import java.awt.image.WritableRaster;
import java.util.Map;
// import org.eclipse.imagen.media.test.OpImageTester;
import org.eclipse.imagen.AreaOpImage;
import org.eclipse.imagen.BorderExtender;
import org.eclipse.imagen.ImageLayout;
import org.eclipse.imagen.KernelJAI;
import org.eclipse.imagen.RasterAccessor;
import org.eclipse.imagen.RasterFormatTag;

/**
 * An OpImage class to perform Gradient operation on a source image.
 *
 * <p>The Kernels cannot be bigger in any dimension than the image data.
 *
 * @see KernelJAI
 */
final class GradientOpImage extends AreaOpImage {

    /** The kernel with which to do the gradient operation. */
    protected KernelJAI kernel_h, kernel_v;

    /** Kernel variables. */
    private int kw, kh;

    /**
     * Creates a GradientOpImage given the image source and the pair of orthogonal gradient kernels. The image
     * dimensions are derived from the source image. The tile grid layout, SampleModel, and ColorModel may optionally be
     * specified by an ImageLayout object.
     *
     * @param source a RenderedImage.
     * @param extender a BorderExtender, or null.
     * @param layout an ImageLayout optionally containing the tile grid layout, SampleModel, and ColorModel, or null.
     * @param kernel_h the horizontal kernel.
     * @param kernel_v the vertical kernel
     */
    public GradientOpImage(
            RenderedImage source,
            BorderExtender extender,
            Map config,
            ImageLayout layout,
            KernelJAI kernel_h,
            KernelJAI kernel_v) {
        super(
                source,
                layout,
                config,
                true,
                extender,
                kernel_h.getLeftPadding(),
                kernel_h.getRightPadding(),
                kernel_h.getTopPadding(),
                kernel_h.getBottomPadding());

        // Local copy of the kernels
        this.kernel_h = kernel_h;
        this.kernel_v = kernel_v;

        //
        // At this point both kernels should be of same width & height
        // so it's enough to get the information from one of them
        //
        kw = kernel_h.getWidth();
        kh = kernel_h.getHeight();
    }

    /**
     * Performs gradient operation on a specified rectangle. The sources are cobbled.
     *
     * @param sources an array of source Rasters, guaranteed to provide all necessary source data for computing the
     *     output.
     * @param dest a WritableRaster tile containing the area to be computed.
     * @param destRect the rectangle within dest to be processed.
     */
    protected void computeRect(Raster[] sources, WritableRaster dest, Rectangle destRect) {
        // Retrieve format tags.
        RasterFormatTag[] formatTags = getFormatTags();

        Raster source = sources[0];
        Rectangle srcRect = mapDestRect(destRect, 0);

        RasterAccessor srcAccessor = new RasterAccessor(
                source, srcRect, formatTags[0], getSourceImage(0).getColorModel());
        RasterAccessor dstAccessor = new RasterAccessor(dest, destRect, formatTags[1], getColorModel());

        switch (dstAccessor.getDataType()) {
            case DataBuffer.TYPE_BYTE:
                byteLoop(srcAccessor, dstAccessor);
                break;
            case DataBuffer.TYPE_INT:
                intLoop(srcAccessor, dstAccessor);
                break;
            case DataBuffer.TYPE_SHORT:
                shortLoop(srcAccessor, dstAccessor);
                break;
            case DataBuffer.TYPE_USHORT:
                ushortLoop(srcAccessor, dstAccessor);
                break;
            case DataBuffer.TYPE_FLOAT:
                floatLoop(srcAccessor, dstAccessor);
                break;
            case DataBuffer.TYPE_DOUBLE:
                doubleLoop(srcAccessor, dstAccessor);
                break;

            default:
        }

        // If the RasterAccessor object set up a temporary buffer for the
        // op to write to, tell the RasterAccessor to write that data
        // to the raster no that we're done with it.
        if (dstAccessor.isDataCopy()) {
            dstAccessor.clampDataArrays();
            dstAccessor.copyDataToRaster();
        }
    }

    private void byteLoop(RasterAccessor src, RasterAccessor dst) {
        int dwidth = dst.getWidth();
        int dheight = dst.getHeight();
        int dnumBands = dst.getNumBands();

        float[] kdata_h = kernel_h.getKernelData();
        float[] kdata_v = kernel_v.getKernelData();

        byte dstDataArrays[][] = dst.getByteDataArrays();
        int dstBandOffsets[] = dst.getBandOffsets();
        int dstPixelStride = dst.getPixelStride();
        int dstScanlineStride = dst.getScanlineStride();

        byte srcDataArrays[][] = src.getByteDataArrays();
        int srcBandOffsets[] = src.getBandOffsets();
        int srcPixelStride = src.getPixelStride();
        int srcScanlineStride = src.getScanlineStride();

        for (int k = 0; k < dnumBands; k++) {
            byte dstData[] = dstDataArrays[k];
            byte srcData[] = srcDataArrays[k];

            int srcScanlineOffset = srcBandOffsets[k];
            int dstScanlineOffset = dstBandOffsets[k];

            for (int j = 0; j < dheight; j++) {
                int srcPixelOffset = srcScanlineOffset;
                int dstPixelOffset = dstScanlineOffset;

                for (int i = 0; i < dwidth; i++) {
                    float f_h = 0.0f;
                    float f_v = 0.0f;

                    int kernelVerticalOffset = 0;
                    int imageVerticalOffset = srcPixelOffset;

                    for (int u = 0; u < kh; u++) {
                        int imageOffset = imageVerticalOffset;

                        for (int v = 0; v < kw; v++) {

                            f_h += ((int) srcData[imageOffset] & 0xff) * kdata_h[kernelVerticalOffset + v];
                            f_v += ((int) srcData[imageOffset] & 0xff) * kdata_v[kernelVerticalOffset + v];

                            imageOffset += srcPixelStride;
                        }

                        kernelVerticalOffset += kw;
                        imageVerticalOffset += srcScanlineStride;
                    }

                    // Do the Gradient
                    float sqr_f_h = f_h * f_h;
                    float sqr_f_v = f_v * f_v;
                    float result = (float) Math.sqrt(sqr_f_h + sqr_f_v);

                    int val = (int) (result + 0.5f); // Round
                    if (val < 0) {
                        val = 0;
                    } else if (val > 255) {
                        val = 255;
                    }
                    dstData[dstPixelOffset] = (byte) val;
                    srcPixelOffset += srcPixelStride;
                    dstPixelOffset += dstPixelStride;
                }
                srcScanlineOffset += srcScanlineStride;
                dstScanlineOffset += dstScanlineStride;
            }
        }
    }

    private void shortLoop(RasterAccessor src, RasterAccessor dst) {
        int dwidth = dst.getWidth();
        int dheight = dst.getHeight();
        int dnumBands = dst.getNumBands();

        float[] kdata_h = kernel_h.getKernelData();
        float[] kdata_v = kernel_v.getKernelData();

        short dstDataArrays[][] = dst.getShortDataArrays();
        int dstBandOffsets[] = dst.getBandOffsets();
        int dstPixelStride = dst.getPixelStride();
        int dstScanlineStride = dst.getScanlineStride();

        short srcDataArrays[][] = src.getShortDataArrays();
        int srcBandOffsets[] = src.getBandOffsets();
        int srcPixelStride = src.getPixelStride();
        int srcScanlineStride = src.getScanlineStride();

        for (int k = 0; k < dnumBands; k++) {
            short dstData[] = dstDataArrays[k];
            short srcData[] = srcDataArrays[k];
            int srcScanlineOffset = srcBandOffsets[k];
            int dstScanlineOffset = dstBandOffsets[k];
            for (int j = 0; j < dheight; j++) {
                int srcPixelOffset = srcScanlineOffset;
                int dstPixelOffset = dstScanlineOffset;
                for (int i = 0; i < dwidth; i++) {
                    float f_h = 0.0f;
                    float f_v = 0.0f;
                    int kernelVerticalOffset = 0;
                    int imageVerticalOffset = srcPixelOffset;
                    for (int u = 0; u < kh; u++) {
                        int imageOffset = imageVerticalOffset;
                        for (int v = 0; v < kw; v++) {
                            f_h += (srcData[imageOffset]) * kdata_h[kernelVerticalOffset + v];
                            f_v += (srcData[imageOffset]) * kdata_v[kernelVerticalOffset + v];
                            imageOffset += srcPixelStride;
                        }
                        kernelVerticalOffset += kw;
                        imageVerticalOffset += srcScanlineStride;
                    }

                    // Do the Gradient
                    float sqr_f_h = f_h * f_h;
                    float sqr_f_v = f_v * f_v;
                    float result = (float) Math.sqrt(sqr_f_h + sqr_f_v);

                    int val = (int) (result + 0.5f); // Round
                    if (val < Short.MIN_VALUE) {
                        val = Short.MIN_VALUE;
                    } else if (val > Short.MAX_VALUE) {
                        val = Short.MAX_VALUE;
                    }

                    dstData[dstPixelOffset] = (short) val;
                    srcPixelOffset += srcPixelStride;
                    dstPixelOffset += dstPixelStride;
                }
                srcScanlineOffset += srcScanlineStride;
                dstScanlineOffset += dstScanlineStride;
            }
        }
    }

    private void ushortLoop(RasterAccessor src, RasterAccessor dst) {
        int dwidth = dst.getWidth();
        int dheight = dst.getHeight();
        int dnumBands = dst.getNumBands();

        float[] kdata_h = kernel_h.getKernelData();
        float[] kdata_v = kernel_v.getKernelData();

        short dstDataArrays[][] = dst.getShortDataArrays();
        int dstBandOffsets[] = dst.getBandOffsets();
        int dstPixelStride = dst.getPixelStride();
        int dstScanlineStride = dst.getScanlineStride();

        short srcDataArrays[][] = src.getShortDataArrays();
        int srcBandOffsets[] = src.getBandOffsets();
        int srcPixelStride = src.getPixelStride();
        int srcScanlineStride = src.getScanlineStride();

        for (int k = 0; k < dnumBands; k++) {
            short dstData[] = dstDataArrays[k];
            short srcData[] = srcDataArrays[k];
            int srcScanlineOffset = srcBandOffsets[k];
            int dstScanlineOffset = dstBandOffsets[k];
            for (int j = 0; j < dheight; j++) {
                int srcPixelOffset = srcScanlineOffset;
                int dstPixelOffset = dstScanlineOffset;
                for (int i = 0; i < dwidth; i++) {
                    float f_h = 0.0f;
                    float f_v = 0.0f;
                    int kernelVerticalOffset = 0;
                    int imageVerticalOffset = srcPixelOffset;
                    for (int u = 0; u < kh; u++) {
                        int imageOffset = imageVerticalOffset;
                        for (int v = 0; v < kw; v++) {
                            f_h += (srcData[imageOffset] & 0xffff) * kdata_h[kernelVerticalOffset + v];
                            f_v += (srcData[imageOffset] & 0xffff) * kdata_v[kernelVerticalOffset + v];
                            imageOffset += srcPixelStride;
                        }
                        kernelVerticalOffset += kw;
                        imageVerticalOffset += srcScanlineStride;
                    }

                    // Do the Gradient
                    float sqr_f_h = f_h * f_h;
                    float sqr_f_v = f_v * f_v;
                    float result = (float) Math.sqrt(sqr_f_h + sqr_f_v);

                    int val = (int) (result + 0.5f); // Round
                    if (val < 0) {
                        val = 0;
                    } else if (val > 0xffff) {
                        val = 0xffff;
                    }

                    dstData[dstPixelOffset] = (short) val;
                    srcPixelOffset += srcPixelStride;
                    dstPixelOffset += dstPixelStride;
                }
                srcScanlineOffset += srcScanlineStride;
                dstScanlineOffset += dstScanlineStride;
            }
        }
    }

    private void intLoop(RasterAccessor src, RasterAccessor dst) {
        int dwidth = dst.getWidth();
        int dheight = dst.getHeight();
        int dnumBands = dst.getNumBands();

        float[] kdata_h = kernel_h.getKernelData();
        float[] kdata_v = kernel_v.getKernelData();

        int dstDataArrays[][] = dst.getIntDataArrays();
        int dstBandOffsets[] = dst.getBandOffsets();
        int dstPixelStride = dst.getPixelStride();
        int dstScanlineStride = dst.getScanlineStride();

        int srcDataArrays[][] = src.getIntDataArrays();
        int srcBandOffsets[] = src.getBandOffsets();
        int srcPixelStride = src.getPixelStride();
        int srcScanlineStride = src.getScanlineStride();

        for (int k = 0; k < dnumBands; k++) {
            int dstData[] = dstDataArrays[k];
            int srcData[] = srcDataArrays[k];
            int srcScanlineOffset = srcBandOffsets[k];
            int dstScanlineOffset = dstBandOffsets[k];
            for (int j = 0; j < dheight; j++) {
                int srcPixelOffset = srcScanlineOffset;
                int dstPixelOffset = dstScanlineOffset;
                for (int i = 0; i < dwidth; i++) {
                    float f_h = 0.0f;
                    float f_v = 0.0f;
                    int kernelVerticalOffset = 0;
                    int imageVerticalOffset = srcPixelOffset;
                    for (int u = 0; u < kh; u++) {
                        int imageOffset = imageVerticalOffset;
                        for (int v = 0; v < kw; v++) {
                            f_h += ((int) srcData[imageOffset]) * kdata_h[kernelVerticalOffset + v];
                            f_v += ((int) srcData[imageOffset]) * kdata_v[kernelVerticalOffset + v];
                            imageOffset += srcPixelStride;
                        }
                        kernelVerticalOffset += kw;
                        imageVerticalOffset += srcScanlineStride;
                    }

                    // Do the Gradient
                    float sqr_f_h = f_h * f_h;
                    float sqr_f_v = f_v * f_v;
                    float result = (float) Math.sqrt(sqr_f_h + sqr_f_v);

                    dstData[dstPixelOffset] = (int) (result + 0.5f); // Round
                    srcPixelOffset += srcPixelStride;
                    dstPixelOffset += dstPixelStride;
                }
                srcScanlineOffset += srcScanlineStride;
                dstScanlineOffset += dstScanlineStride;
            }
        }
    }

    private void floatLoop(RasterAccessor src, RasterAccessor dst) {
        int dwidth = dst.getWidth();
        int dheight = dst.getHeight();
        int dnumBands = dst.getNumBands();

        float[] kdata_h = kernel_h.getKernelData();
        float[] kdata_v = kernel_v.getKernelData();

        float dstDataArrays[][] = dst.getFloatDataArrays();
        int dstBandOffsets[] = dst.getBandOffsets();
        int dstPixelStride = dst.getPixelStride();
        int dstScanlineStride = dst.getScanlineStride();

        float srcDataArrays[][] = src.getFloatDataArrays();
        int srcBandOffsets[] = src.getBandOffsets();
        int srcPixelStride = src.getPixelStride();
        int srcScanlineStride = src.getScanlineStride();

        for (int k = 0; k < dnumBands; k++) {
            float dstData[] = dstDataArrays[k];
            float srcData[] = srcDataArrays[k];
            int srcScanlineOffset = srcBandOffsets[k];
            int dstScanlineOffset = dstBandOffsets[k];
            for (int j = 0; j < dheight; j++) {
                int srcPixelOffset = srcScanlineOffset;
                int dstPixelOffset = dstScanlineOffset;
                for (int i = 0; i < dwidth; i++) {
                    float f_h = 0.0f;
                    float f_v = 0.0f;
                    int kernelVerticalOffset = 0;
                    int imageVerticalOffset = srcPixelOffset;
                    for (int u = 0; u < kh; u++) {
                        int imageOffset = imageVerticalOffset;
                        for (int v = 0; v < kw; v++) {
                            f_h += (srcData[imageOffset]) * kdata_h[kernelVerticalOffset + v];
                            f_v += (srcData[imageOffset]) * kdata_v[kernelVerticalOffset + v];
                            imageOffset += srcPixelStride;
                        }
                        kernelVerticalOffset += kw;
                        imageVerticalOffset += srcScanlineStride;
                    }

                    // Do the Gradient
                    float sqr_f_h = f_h * f_h;
                    float sqr_f_v = f_v * f_v;
                    float result = (float) Math.sqrt(sqr_f_h + sqr_f_v);

                    dstData[dstPixelOffset] = result;
                    srcPixelOffset += srcPixelStride;
                    dstPixelOffset += dstPixelStride;
                }
                srcScanlineOffset += srcScanlineStride;
                dstScanlineOffset += dstScanlineStride;
            }
        }
    }

    private void doubleLoop(RasterAccessor src, RasterAccessor dst) {
        int dwidth = dst.getWidth();
        int dheight = dst.getHeight();
        int dnumBands = dst.getNumBands();

        float[] kdata_h = kernel_h.getKernelData();
        float[] kdata_v = kernel_v.getKernelData();

        double dstDataArrays[][] = dst.getDoubleDataArrays();
        int dstBandOffsets[] = dst.getBandOffsets();
        int dstPixelStride = dst.getPixelStride();
        int dstScanlineStride = dst.getScanlineStride();

        double srcDataArrays[][] = src.getDoubleDataArrays();
        int srcBandOffsets[] = src.getBandOffsets();
        int srcPixelStride = src.getPixelStride();
        int srcScanlineStride = src.getScanlineStride();

        for (int k = 0; k < dnumBands; k++) {
            double dstData[] = dstDataArrays[k];
            double srcData[] = srcDataArrays[k];
            int srcScanlineOffset = srcBandOffsets[k];
            int dstScanlineOffset = dstBandOffsets[k];
            for (int j = 0; j < dheight; j++) {
                int srcPixelOffset = srcScanlineOffset;
                int dstPixelOffset = dstScanlineOffset;

                for (int i = 0; i < dwidth; i++) {
                    double f_h = 0.0;
                    double f_v = 0.0;
                    int kernelVerticalOffset = 0;
                    int imageVerticalOffset = srcPixelOffset;
                    for (int u = 0; u < kh; u++) {
                        int imageOffset = imageVerticalOffset;
                        for (int v = 0; v < kw; v++) {
                            f_h += (srcData[imageOffset]) * kdata_h[kernelVerticalOffset + v];
                            f_v += (srcData[imageOffset]) * kdata_v[kernelVerticalOffset + v];
                            imageOffset += srcPixelStride;
                        }
                        kernelVerticalOffset += kw;
                        imageVerticalOffset += srcScanlineStride;
                    }

                    // Do the Gradient
                    double sqr_f_h = f_h * f_h;
                    double sqr_f_v = f_v * f_v;
                    double result = Math.sqrt(sqr_f_h + sqr_f_v);

                    dstData[dstPixelOffset] = result;
                    srcPixelOffset += srcPixelStride;
                    dstPixelOffset += dstPixelStride;
                }
                srcScanlineOffset += srcScanlineStride;
                dstScanlineOffset += dstScanlineStride;
            }
        }
    }

    //     public static OpImage createTestImage(OpImageTester oit) {
    //         float data_h[] = {-1.0f, -2.0f, -1.0f,
    //                            0.0f,  0.0f,  0.0f,
    //                            1.0f,  2.0f,  1.0f};
    //         float data_v[] = {-1.0f, 0.0f, 1.0f,
    //                           -2.0f, 0.0f, 2.0f,
    //                           -1.0f, 0.0f, 1.0f};

    //         KernelJAI kern_h = new KernelJAI(3,3,data_h);
    //         KernelJAI kern_v = new KernelJAI(3,3,data_v);

    //         return new GradientOpImage(oit.getSource(), null, null,
    //                                    new ImageLayout(oit.getSource()),
    //                                    kern_h, kern_v);
    //     }

    //     public static void main(String args[]) {
    //         String classname = "org.eclipse.imagen.media.opimage.GradientOpImage";
    //         OpImageTester.performDiagnostics(classname,args);
    //     }
}
